Import XPG4-compliant basename(3) and dirname(3) from OpenBSD.

The man pages need some adjustments.

PR:		12960, 12962
Submitted by:	James Howard <howardjp@wam.umd.edu>
Obtained from:	OpenBSD

1 files changed, 106 insertions, 0 deletions

diff --git a/lib/libc/gen/dirname.3 b/lib/libc/gen/dirname.3
new file mode 100644
index 0000000..f209019
--- /dev/null
+++ b/lib/libc/gen/dirname.3
@@ -0,0 +1,106 @@
+.\"
+.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. The name of the author may not be used to endorse or promote products
+.\"    derived from this software without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+.\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+.\" THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+.\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+.\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+.\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+.\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\" $OpenBSD: dirname.3,v 1.9 2000/04/18 03:01:25 aaron Exp $
+.\" $FreeBSD$
+.\"
+.Dd August 17, 1997
+.Dt DIRNAME 3
+.Os
+.Sh NAME
+.Nm dirname
+.Nd extract the directory portition of a pathname
+.Sh SYNOPSIS
+.Fd #include <libgen.h>
+.Ft char *
+.Fn dirname "const char *path"
+.Sh DESCRIPTION
+The
+.Fn dirname
+function
+is the converse of
+.Xr basename 3 ;
+it returns a pointer to the parent directory of the pathname pointed to by
+.Ar path .
+Any trailing
+.Sq \&/
+characters are not counted as part of the directory
+name.
+If
+.Ar path
+is a null pointer, the empty string, or contains no
+.Sq \&/
+characters,
+.Fn dirname
+returns a pointer to the string
+.Qq \&. ,
+signifying the current directory.
+.Sh RETURN VALUES
+On successful completion,
+.Fn dirname
+returns a pointer to the parent directory of
+.Ar path .
+.Pp
+If
+.Fn dirname
+fails, a null pointer is returned and the global variable
+.Va errno
+is set to indicate the error.
+.Sh ERRORS
+The following error codes may be set in
+.Va errno :
+.Bl -tag -width Er
+.It Bq Er ENAMETOOLONG
+The path component to be returned was larger than
+.Dv MAXPATHLEN .
+.El
+.Sh WARNINGS
+.Fn dirname
+returns a pointer to internal static storage space that will be overwritten
+by subsequent calls (each function has its own separate storage).
+.Pp
+Other vendor implementations of
+.Fn dirname
+may modify the contents of the string passed to
+.Fn dirname ;
+this should be taken into account when writing code which calls this function
+if portability is desired.
+.Sh SEE ALSO
+.Xr basename 1 ,
+.Xr dirname 1 ,
+.Xr basename 3
+.Sh STANDARDS
+The
+.Fn dirname
+function conforms to
+.St -xpg4.2 .
+.Sh HISTORY
+The
+.Fn dirname
+function first appeared in
+.Ox 2.2 .
+.Sh AUTHOR
+Todd C. Miller <Todd.Miller@courtesan.com>